Summary In the late evening of 22 August 2001, the loaded tanker CoralTrader with a U.S. pilot on board departed the Algoma Steel Corporation wharf at Sault Ste.Marie, Ontario with tug assistance, when it struck the port bow of the moored tank barge PML2501. The Coral Trader sustained moderate damage, but caused no pollution. No one was injured. Ce rapport est galement disponible en franais. Other Factual Information Particulars of the Vessels Description of the Vessels Photo1. Forward view from Coral Trader's Bridge The Coral Trader is an ocean-going chemical tanker with its bridge, accommodation and machinery located aft of its cargo tanks. It is fitted with a single rudder and its main engine drives a controllable-pitch, left-handed propeller. The vessel was moored in a southerly direction along the western side and southern limit of the Algoma Steel Corporation wharf. Its intended voyage was downbound through the SooLocks with a cargo of coal tar in its centre tanks. The empty side tanks, together with the continuous double bottom, provide double hull environmental protection. The PML 2501 is a square-ended, non-propelled petroleum tank barge of steel construction. It was moored in a westerly direction along the southern end of the Algoma Steel Corporation wharf (see Photo 1). Sault Ste. Marie - Area of the Occurrence The harbour of Sault Ste. Marie, Ontario is located on the St. Marys River, which is the outlet of Lake Superior, connecting it with Lake Huron. The river is bounded to the north and east by the province of Ontario, and to the south and west by the state of Michigan, United States. The Algoma Steel Corporation wharf is at the north western side of the canal systems which by-pass the St.Marys Falls. The tanker CoralTrader and the barge PML2501 were berthed at this wharf (see Figure1). Figure1. Area of occurrence showing initial location of Coral Trader and PML2501 The Sault Ste. Marie (Canada) Canal which passes north of the St.Marys Falls is closed to through navigation. All vessels must utilize the St.Marys Falls Canal and its lock systems (SooLocks) in United States territory south of the St.Marys Falls. The St.Marys River waterway is within International District No.3 which is a compulsory pilotage area. Every foreign trade vessel must engage a United States or Canadian Registered pilot for the route being navigated within this area of the GreatLakes. There are 19U.S. pilots and 4Canadian pilots assigned to the district. Vessel traffic services are provided by the United States Coast Guard. All salt water vessels transiting the lock systems along the St.Marys River which are not equipped with either bow thruster or stern thrusters, are required to be assisted by one or more tugs to ensure that full control of the vessel is maintained at all times.2 Occurrence On the evening of 22 August 2001, the Coral Trader was berthed port side to the Algoma Steel Corporation wharf and headed south toward the St.Marys River. Its bow protruded approximately 15 to 20m past the end of the wharf, exposing its starboard side to a strong easterly current of 3.0 to 3.5knots. The barge PML 2501 was berthed on the southern side of the wharf and headed west with its square bow approximately 7 to 8m from the outer knuckle of the wharf. At 2308, the Coral Trader had finished loading coal tar and was ready to leave. A U.S. pilot had been aboard for approximately 45minutes and had made himself familiar with the vessel's manoeuvring characteristics from the pilot card. He had discussed the intended departure with the master of the assisting tug Adanac (see Photo 2). However, the tug master indicated that he only received a brief VHF radio communication from the pilot concerning the manoeuvres required for departure, but no formal departure plan was made. The master of the CoralTrader indicated that there was a very brief discussion with the pilot concerning the vessel's departure, however, a departure plan was not prepared. The pilot had taken an average of four or five vessels per season to and from various berths along the Algoma wharf. However, this was his first pilotage assignment from this particular berth at the extreme southern limit of the wharf. He did not fully appreciate the speed of the river current around this end section of the wharf. At the time of departure, the Adanac was positioned forward to push on the bow and port shoulder of the CoralTrader at about 75 to the tanker's line of direction. There was little room for the tug to manoeuvre between the bow of the barge PML2501, the wharf knuckle, and the forward end of the CoralTrader. At 2309, in darkness, clear visibility and calm conditions, the Coral Trader's mooring lines were let go and the tug Adanac began to push ahead on the tanker's port shoulder. The initial engine control order for the CoralTrader was dead slow astern, and the vessel moved astern approximately 3m while the tug pushed the vessel's bow about 6m out from the wharf. At 2311, the engines were set to dead slow ahead. Reportedly, the master had difficulty in hearing the instructions given by the pilot, who was speaking in a low voice. At 2312, the pilot gave the engine order stop then half astern. At about 2314, the tug circled around the starboard quarter of the CoralTrader towards the tanker's stern. Meanwhile, the current swung the CoralTrader's bow back to the wharf. The tug attempted to connect a towline, stern to stern, but the CoralTrader was moving slowly ahead along the side of the wharf. Turbulence from the tanker's propeller prevented the tug's stern from closing quickly enough to pass a connecting towline, but it was eventually secured. The bridge wings were used by both pilot and master to get a good view astern during manoeuvres. At 2316, the main engine was stopped after the tanker had moved approximately 33m ahead. However, the CoralTrader continued to move ahead and further into the cross current. When the vessel was approximately half its length beyond the end of the wharf, the bow began to fall away to port with the current. The master expressed his concerns to the pilot regarding conduct of the vessel movement, as the distance between the barge PML2501 and the CoralTrader began to close rapidly. The master of the CoralTrader informed the pilot that full astern movement was necessary. The engine manoeuvring log showed that at 2319 a slow astern instruction had been made, followed by stop at 2320. At 2323, full astern order was given. The CoralTrader's forward momentum carried it ahead until about 75percent of the vessel passed beyond the end of the wharf. The corner of the wharf acted as a pivot point and the vessel continued to swing to port with the current. The vessel struck the barge PML2501. The front of the accommodation superstructure (port side, just above deck level) of the moving tanker caught the port bow corner of the barge, pushing the barge astern and breaking some of its mooring lines. As the full astern control setting took effect, the CoralTrader with tug assist, began backing towards its original berthing location. Photo3. Port-side damage to Coral Trader The remaining barge mooring lines returned the PML2501 forward of her original berthing position as the CoralTrader moved astern, but the fore end of the barge was eventually pushed tight against the wharf. At approximately 2340, the Coral Trader's port side made contact with the port corner of the barge's bow. In continuing its astern manoeuvre while sideswiping the corner of the static barge, the CoralTrader suffered damage to its railings, manifold fittings and vents along the port side of the open deck (see Photo3). At 0005 on 23 August, the Coral Trader was secured to its previous moorings at the Algoma wharf. The normal method of departure from this berth is to use a backspring aft and tug assistance forward to prevent the bow from setting onto the wharf.